Publication Date:
2022-10-14
Description:
Assessing the variations in space and time of groundwater circulation in volcanic islands is
of paramount importance to the description of the hydro-geo-thermal system and
implementation of hydrogeological, geochemical, and volcanic monitoring systems. In
fact, the reliable reconstruction of the groundwater potentiometric surface in such
composite volcanic aquifer systems can enable the identification of the most
advantageous strategies for both the sustainable use of groundwater resources and
the management of volcanic risk. Geographical Information System (GIS) platforms can
support the integration and analysis of many spatial and temporal variables derived from
monitoring of active volcanoes and the elaboration of spatially continuous data. However,
open issues still affect the reliability and general applicability of common spatial
interpolation methods in the case of groundwater potentiometric surfaces. This is
related to the assessment of the main stratigraphic and volcano-tectonic features
affecting the hydraulic head changes. With regard to the dynamically very active Ischia
Island (Italy), this study illustrates a GIS-based hydrogeological approach to identify the
most accurate interpolation method for mapping the potentiometric surface in complex
hydrogeological terrains. The proposed approach has been applied to the existing dataset
(1977–2003) stored by Istituto Nazionale di Geofisica e Vulcanologia. Based on a careful
geological and hydrogeological survey, a total of 267 wells, from 5 to 250 m in depth, were
processed. The data pre-processing involved four meteorological time-series data
(1922–1997) and six long records of piezometric water levels (1930–1994). As a result,
knowledge of the delineation of rather homogeneous stratigraphic and volcano-tectonic
structures at the basin-scale has improved. Thus, new, more reliable potentiometric
surfaces of the four main geothermal areas closest to the coast were produced during
both dry and wet seasons. The reliability of the processed potentiometric surface was then
validated by comparing the spatially continuous data with complementary field data. These
findings point toward an optimal interpolation approach for representing the seasonal and
areal distribution of main hydrogeological parameters in complex aquifer systems. Finally,
insights into variations of hydrological behavior at an active volcanic area will foster an understanding of possible involvement of fresh and thermal waters in triggering phreatic
explosions.
Description:
Published
Description:
883719
Description:
2V. Struttura e sistema di alimentazione dei vulcani
Description:
6V. Pericolosità vulcanica e contributi alla stima del rischio
Description:
JCR Journal
Keywords:
groundwater map
;
hydrothermal system
;
conceptual model
;
volcanic island hydrogeology
;
spatial interpolation
;
GIS
;
Ischia Island
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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